Building a G+2 (Ground floor + 2 upper floors) villa row house with rammed earth load-bearing walls is possible, but achieving it without columns requires careful planning and structural engineering analysis. Here's a breakdown of the feasibility and key considerations:

Feasibility:

• Limited Spans: Rammed earth excels in compression but has limitations in resisting tension. Without columns, achieving large open floor plans or wide spans between walls becomes challenging. A G+2 villa with smaller room sizes and strategically placed walls might be feasible with rammed earth.

Key Considerations for Design:

• Wall Thickness: The thickness of the rammed earth walls will be crucial. Thicker walls provide greater load-bearing capacity but also increase material usage and decrease usable floor space. Structural engineers will perform calculations to determine the minimum safe thickness based on the building height, floor loads, and local building codes.
• Soil Composition: The success of rammed earth construction relies heavily on the soil used. The soil needs to be properly tested to ensure it has the right composition of clay, sand, and gravel for optimal strength and stability.
• Stabilization: While un-stabilized rammed earth can be used for small structures, stabilized rammed earth with natural or cementitious stabilizers is recommended for a G+2 villa. Stabilization enhances the strength and durability of the walls.
• Seismic Considerations: If you're located in an earthquake-prone region, the design needs to incorporate seismic reinforcement techniques like earthbag construction or embedded steel or bamboo elements within the rammed earth walls to improve earthquake resistance.
• Openings (Doors & Windows): Lintels or arches will be necessary above doors and windows to distribute the load around the openings and prevent cracks in the rammed earth walls. Traditional wooden lintels or pre-stressed concrete lintels can be used.
• Roof Design: A lightweight roof system like wood trusses or metal framing is recommended to minimize the load on the rammed earth walls.

Alternative Approaches:

• Combination with Columns: Introducing strategically placed columns at key locations within the design can significantly improve the feasibility of achieving larger floor plans without compromising on structural integrity. Columns can be made from wood, steel, or even stabilized rammed earth depending on the aesthetic and structural requirements.
• Rammed Earth for Internal Walls: Consider using rammed earth for internal, non-load bearing walls to leverage its aesthetic and sustainability benefits while using a more conventional framed structure with columns for the external walls supporting the building weight.

Next Steps:

• Consult with a Structural Engineer: A qualified structural engineer with experience in rammed earth construction is crucial for your project. They can analyze your specific design, perform load calculations, and advise on the feasibility, wall thickness, reinforcement needs, and overall structural stability.
• Research Rammed Earth Construction Techniques: Explore resources and case studies of successful G+2 rammed earth buildings. This will provide valuable insights and design inspiration.

Building a G+2 villa with rammed earth load-bearing walls presents an exciting and sustainable design opportunity. However, careful planning, structural analysis, and potentially a combination with columns or a hybrid approach are essential for a safe and successful outcome.